1. Field of the Invention
This invention relates to a controller for a shock absorber of a vehicle suspension whose damping force is made variable responsive to an outer command.
2. Prior Art
Many controllers for variable damping force shock absorbers have been proposed for various kinds of purposes. In order to stabilize the vehicle attitude, e.g., to prevent a squat, a nosedive or a roll of the body, a controller is proposed which increases the damping force in case of an abrupt start, an abrupt braking or a slaloming. Another controller aimed at ride comfort to decrease the damping force when the vehicle is cruising on a flat road and to increase it when running on a rough road for better damping efficiency of the body vibration. For altering the damping force, the Japanese Published Unexamined Patent Application No. Sho-59-23712, entitled as "Air Suspension Controller", discloses an apparatus for detecting the body condition or the road surface condition with proper sensors, for performing a predetermined algorithm with a computer based on the detected conditions and for altering the air suspension characteristic responsive to the calculation result. The alteration of the air suspension characteristic is realized by altering one of the following measures: the capacity of a surge tank provided at the air suspension; a throttle diameter of a throttle valve provided between the surge tank and an air spring; and the damping force of a shock absorber.